Latch solenoid



p 23, 1958 T. LINDENBERG 2,853,658

LATCH SOLENOID Filed July 1, 1953 INVENTOR ATTORNEYS I 72/500019: A I/YOENBERG United States Patent (1 LATCH SOLENOID Theodore Lindenberg, West Islip, N. Y., assignor to Pickering Associates, Inc., Oceanside, N. Y., a corporation of New York Application July 1, 1953, Serial No. 365,364 2 Claims. 01. 317-487) This invention relates to a latch solenoid by means of which a solenoid, once energized, may be held in its energized position after de-energization of the solenoid coil.

One of the objects of this invention is to provide such a latch structure for use in relay circuits to maintain electrical contact points in either open or closed position solely as a result of an initial impulse in the solenoid coil.

Another object of this invention is to provide a latching solenoid having means actuated by the energization of a second coil for releasing it from its latched position.

A further object of this invention is to provide a latching solenoid which may operate for desired periods without the latching feature and one which is simple in design and certain in operation.

Other and further objects of this invention will become apparent from a reading of the below specifications and a consideration of the drawings. These drawings specifically are:

Fig. 1 is a sectional view of the invention, certain parts of which are shown in elevation. The invention is here shown in latched position. t

Fig. 2 is a partial section taken on line 2-2 of Fig. l.

The structure of this invention generally has two cooperative solenoid units. The armature of one serves to operate switches, etc., in the usual manner and has a latching mechanism holding it in its energized position. The second unit, upon energization, eiTects release of the first from its latched position.

Turning to Fig. 1, we see the entire structure identified by the numeral 1. The main solenoid includes annular actuating coil 2 and main solenoid armature 4. The releasing mechanism primarily includes annular latching release coil 3 and releasing armature 30. All of these operate in conjunction with the central mutual core structure 8. This core 8 has its upper and lower surfaces bevelled concavely and convexly respectively.

The main armature 4 is located at least partially within actuating coil 2 and is so disposed as to be able to move along the axis of actuating coil 2. Its lower surface is bevelled to correspond to the upper surface of core 8. Armature 4 has a plunger 5 thereon extending downwardly from the armature itself and through the .core and releasing armature 30, as will be described below. Plunger 5 serves in the customary manner to actuate whatever switch mechanisms or the like are controlled by the solenoid. Thus, plunger 5 projects downwardly into these switch mechanisms which are generally depicted by the dotted lines 11.

The overall core structure creating a path for the flux of actuating coil 2 is provided by the central core structure 8, the core end pieces 6 and 9, and the outer flux member 22, all of which are annular and preferably made of magnetic metal such as iron.

The central core 8 has a spring recess 12 to provide space for the biasing coil spring 13 disposed around plunger 5. One end of spring 13 rests upon the end of spring recess 12; the other, upon the annular flattened surface 14 of the main solenoid armature 4. Spring 13 will thus normally bias solenoid armature 4 upwardly and away from core 8. Upon energization of actuating coil 12, armature 4 and armature plunger 5 are caused to move downwardly against the opposing force of spring 13.

Releasing armature 30 is located at least partially within releasing solenoid coil 3. It has a bore therethrough for passage of plunger 5. The upper surface 20 of the releasing armature 30 is annularly bevelled and has an angle corresponding to the angle of bevel of the lower surface of core 8.

Core 8 has a second spring recess 15 located in the lower portion of the core and about its outer diameter. Within this recess and disposed about core 8 is a second coil spring 17. The upper end of spring 17 rests against the annular flattened end surface 16 of recess 15, and the lower end rests on the washer 25, pressing upon the upper edge of releasing armature 30. Thus, releasing armature 30 is normally biased downwardly and away from the central mutual core structure.

The structure creating a path for the flux of the latch release coil 3 is through the mutual core 8, end pieces 6 and 7, and outer flux member 22.

Core member 8 has central bore 24 therethrough, preferably located within the exact center of the core and axially aligned with the coils 2 and 3. Armature plunger 5 is disposed within this bore. Plunger 5 contains a latching slot 18 drilled therethrough, the upper and lower ends of which are shown by numerals 19 and 20. Disposed within this slot is a flexible spring steel latch or fork 21, preferably of U shape. Latch 21 is of a length but slightly less than the distance between ends 19 and 20. The latch legs 23 are biased outwardly, i. e. radially. Latch legs 23 have latching detents 26 thereon at their lower ends. The normal size of the spring latch 21 as measured across the outer edges of detents 26 is greater than the diameter of the bore 24 of core 8. Its thickness is slightly less than the width of latching slot 18.

Detents 26 have latching surfaces 27 thereon that are substantially perpendicular to legs 23. They also have bevelled releasing surfaces 28 as shown in Fig. 1. Core 'ice 8 has an annular latching point 29 for engagement with latch surfaces 27. This engagement occurs when the solenoid is in latched position as shown in Fig. 1. The releasing armature 30 has a bevelled releasing surface 31 for engagement with releasing surfaces 28, as will hereinafter be disclosed.

The operation of the solenoid is as follows:

Assume that the main armature 4 and plunger 5 are in unlatched position, as shown by the dotted lines in Fig. 1. When actuating coil 2 is energized, the main solenoid armature 4 and the armature plunger 5 move downwardly. As plunger 5 moves downwardly, it carries latch 21 to the point where its latching surface 27 is below the core latching point 29. Latching detents 26 will then be free to move radially, as biased, so that latching surfaces 27 will engage core latching point 29 of the central core structure 8. If actuating coil 2 is then deenergized, coil spring 13 acting between armature 4 and core 8 will tend to separate armature 4 and core 8 by forcing armature 4 upwardly, but, due to the engagement of detents 26 and latching point 29, such motion is prevented. Surface 20 of plunger 5 presses against the lower ends of latch legs 23 and is blocked from further upward movement. Since plunger 5 is connected to armature 4, armature 4 will be locked in its energized position. Plunger 5 being held in its lower energized position, will continue to act upon the switching mechanisms 11 as though coil 2 were still energized.

Armature 4 and plunger 5 are released by forcing detents 26 inwardly until latching surfaces 27 no longer engage core latching point 29 so as to free plunger 5 3 for u pward,moti on as biased This may he effectedby energizing latch' release coil"'3. Releasing armature 30 then moves upwardly against the action of coil spring 17 causing the bevelled releasing surface 31 to press against the corresponding bevelled releasinglsurfaces 28 of latch 21. Inte'raction' of the two bevelled surfaces 28 and 31 results inlatching'detents' 26 being forced inwardly to the poiiit that latching surfaces' 27 no longer engage core latching point 29; When'this occurs, lugs 26 arefr'ee to travel upwardly Within core 24 and are so urged by the force of coil spring 13 upon armature 4. Armature land plungerthen assume their released first position and Will remain in that position even though coil 3 may be deenergiz'edl and releasing armature 30 moves downwardly to its normal position. The cycle can then be repeated. i i

If,':at an particular time it is desired to operate this solenoid" structure 'i'wit'ho ut" the latching feature, this may be accomplished by' inaintaiiii'ng' latch release coil 3 continually'lenergized.' 'Under'such circumstances releasing armarureso isfheld in its upward position, theibevelled releasing "shrface; 31 being substantially "in'coutact with the lower surface of core 8, especially at core latching point 29. Inthis instance the deteiits' 26'with their la'tching surfaces 27 will be blo'c'k'ed from moving outwardly and into" latching relationship with latchingpoint' 29 by the presence thereof 'ofsarrriature "30 and surface" 31, even though plunger 5 carries thelatch' 21 far enough down upon energi zati onof actuating coil 2.

As canbe readily seen, various modifications of this invention'can be made without dpartingfrom thespirit thereof." Among other things, the spring latch may take other forms and still accomplish its 'p'urposejLikewise, the' means for forcing the latch"structure' inwardly may take'bbviou's terms "other than a: separate releasing solet hhh, r

I claim:

1. In an apparatus of the character described, a solenoid actuating coil, a solenoid core havin'ga' bore disposed in operative relation to "'said' coil, an" armature'fat least partially within said 011 and iaaxral alignnien titherewith,

UNITED STATES PATENTS.

871,378 Thullen Nov. 19, 1907 1,052,595, Lanphier Feb.c1l,;l9l3 2,448,959. Conlan se 1948 40 2,632,821 Wright Man-24, 1953 meansvtending to separate. said core and said armature,.a plunger having a slot secured to said armature and slidably within said bore, a latching surface forming part of said core adjacent one end of said bore, a resilient substantially U-shaped member and outwardly turned detent portions forming the ends of the legs thereof housed within said plunger, wherebyon projecting said plunger through said borethe detentportions will move outwardly of said slots and engage said latching surface, and a latch releasing means adjacent said latching surface.

2. In an apparatus ofthe character described, a sole: noid actuating coil, a solenoid core havinga bore .disposed in operative relation to said coil, an armature at least partially within said coil and in axial alignment therewith, means tending to separate said core and said armature, a plungerhaving a slot secured to said armature and slidably within said bore, a latching surface forming part of said core adjacent one end of said bore, a positively biased radially-acting latching means housed within'saidplunger for retaining engagement with said.

latching surface when said coil is energized and said plunger ispr'ojected through said bore,.a releasing coil in operative relation to said core, a releasing armature having a here to accommodate said plunger at least par-, tially within said releasingcoil, means tending to, separate said core and said. releasing armature, and latch releasing c amm ingmeans forming part of said armature adjacent an end of said armature bore, wherebyon energizingsaid releasing coilthe releasing armature moves toward said coresuch that said plunger projects into said bore and said latch camming means cams said latch into said plunger.

References Cited in the file of this patent 

